Projection lamp



June 7 1927.

H. WORKMAN PROJECTION LAMP Filed May 15. 1926 6 Sheets-Sheet l INVENTOP HQMG/ [110mm Il T W I Arron/mam June 7 1927.-

H. WORKMAN FROJECTIOW LAMP Filed May 15, 1926 .6 Sheets-Sheet 2 Ali [N709 Ha/1A1 [/5 WW W 1,631,905 June 7 1927' H. WORKMAN PROJECTION LAMP Filed May 15, 1926 6 Sheets-Sheet 3 /NVEN7DP A 77"OP/VEX5 June 7 1927;

H. WORKMAN PROJECTION LAMP 6 Sheets- Sheet 4 Filed May 15, 1926 awnvmo v Hamli {MM 19y W 4 4 4770mm June 7, 1927. 1,631,905

H. WORKMAN PROJECTION LAMP Filed May 15, 1926 6 Sheets-Sheet 5 A Tm/PNE X5 June 7, 1927.

WORKM KN PROJECTION LAMP Filed May 15, 19 26 6 Sheets-Sheet 6 ATIOQNEXS Patented June 7,1927.

T'HA'ROLD 'WOR'KMAFN; or GLASGOW; SCOTLAND. I

i momc'rmiw mar.

a ucmameafmy '15, 1526, semi m. 1Q9,446, ,and in Great Britain May 14, 1925.

This invention relates to motor car head lamps and more definitely speaking 'to head lamps of the class furnished With a para bolic or a 'ap roriiniately"parabolic reflector with a concentrated light source, preferably an incandescent electric lamphaving a single pillar filament, which is adjusted imposition to lie along the axis ofthe reflector and tofextend either backwardly or forwardly from the focus of the reflector. When such a filament is set so that it extends backwards from "the focus "along the aXis of thef parabolic reflector andthe upper half of thelreflector or lar'np front is covered over, a Hat topped beam "of light will be. projected by the lower halfjof the reflector. In a siinilaufashion when g'the filament is set so that it extends forwvardly from the focus along the axis ofthe' p'arabolie reflector and the, lower half of the reflector or of the" lamp front is covered over, a substantiallyhflat topped beam will also be projected from"thefupperfhalt of the reflector upon-an object at a distance of sayQO feetor niore in front'of the'lamp. The "main object of thefpresent invention is to arrange a' motorfcar 'heiiddamp'of the class referred toabov'e so as to give a 'full lightbeam and yet render it 'poss'ible 'for i the driver to cut out at the. reflected rising light which forms the upper half of the light beam. The invention further aims at enabling the light so cut out not. to be wasted. but tobe used to the best advantage, either by adding penetration to the flat topped beamfor preferably by increasing the width of thatb'eam and the illumination of the roadway near jto thec'ary and if, desired partly in providing subdued rising light of similar or greateudispersidn and much reduced penetration; p 1

With these objects in View, according to the present invention a'moto'rca'r' headlain'p of the class already: referred to provided vwith a inovablescreen operating within the reflector of the lamp and arranged to he controlled from the drivers "seat in a way that when in one; position, whieh rnay be termed the closed position,"thefstreen forms a hood-shaped cover lying'substam tially between the light source and one half of the surface of the reflector; and when in another position; whichfmay be called the ev position, ei' a d. l enialle s t e light frointhe source free access was whole but almost the VhOl 0f, lthe said halffof the surface ofthe' reflector. The movable 's'c'reen" does not necessarily intercept all the light cont-rolled by it di'ii ingthe passage of the lightb'etween the filament and the half of the reflector in question, some light frnay pass on to the rearward portion of the reflector and be intercepted'fby the 'inovable screen after thelight has been reflected. This state of affairs is intended tobeim "eluded injthe above statement that the'screen lies substantially between the light source and one half of the surfaceof the reflector. The screen preferably arranged so that when in the openiposition the bulb can be easily removed and replaced Without idisturbing thescreen or its supports or'its operating mechanism. The movable screen may be arranged in some forms of lamp in' accordance with the invent-ion so that when it is in the closed position'itjco'versthe upper half of the frontof the bulb, thereby cutting out direct rising llightirom the fila- 'ment, but "this is not necessary as such light does not"produce objectionable glare and it is preferably arranged toano'w a clear path ."for such rays through the amp front? The movable screen in the elosedwp'osition is prefera-bly arrariged so that the hood-shaped cover formed by it surrounds thehalfof the bulb fairly closely at; its forwardedge, thereby preventing-much light fromv the central portion of the reflector fronr'being projected upwards frorn'within it. For this reason itmay bef'preferable in some constructions'to fmake the higher candle power 'bulbs'jof elongated form rather than to increase their diarneter. Any members fo'rin- 7 ing part of the movable screen orassociated with 'the movable screen Which remain be tween the light source "and the reflector when the Zs creen is in the open position, are preferably'fiountedsothat in that position they lie in or near'to the vertical axial plane of the reflector. VVhen so'situa'ted thesemm; produce radial shadow bars in avertien or' nearly vertical position in the "1ight beanr'and these'shadow-bars can be lat- *erally; spread; and in effect obliterated-by using ahvertieallygroevea 'or ribbed front *glass. and when the flattop'ped beam is pro j 'e cted definition ofit'supper'edge is not injuriously affected.

v 3 Such (anthers-should T not 5 be arranged "to lie in or near tdthe'hori'zonta1 axial plane of the reflector as the shadow bars produced by them when so situated cannot be removed by a diffusing front glass in the ordinary way so as to obtain a good full light'beam without destroying the definition of the upper edge of the flat topped beam when such is in use, thereby defeating'the object ofthe invention. I

In any form of lamp in accordance with the present invention, the movable screen may be operated from the drivers seat by any suitable means such as wires or levers, Bowden wires, electric solenoid and plunger, or by air or other fluid suction or pressure.

In order that the invention may be more clearly understood and readily carried into effect, some examples of motor car head lamps in accordance therewith will now be described with reference to the accompanying drawings which illustrate examples of the forms of screen already referred to and in which s Figure 1 is a central vertical section of one form of lamp in accordance with the invention showing the reflector, the lamp bulb, the movable screen and its operating mechanism. In this figure the screen is in the closed position;

Figure2 is a similar view with the screen in the open position;

Figure 3 is a vertical section on the line IIIIII in Figure 2;

Figure & is a plan view with the reflector in section of a somewhat modified form of lamp in accordance with the invention;

Figure 5 is a central vertical section of the same;

Figure 6 is a rear view of Figure 1 with the reflector omitted;

Figure 7 is a central. vertical section show ing yet a third form of lamp in accordance with the invention;

Figure 8 is an elevation of the lamp looked at from the mouth of the reflector;

Figure 9 is an elevation of the rear of Figure 7 taken in the direction shown by the arrow and illustrating the operating mechanism; while Figure 10 is a central vertical section of a fourth form of the lamp;

Figure 11 is a plan of the same, and

Figure 12 is a central vertical section of yet a further construction of lamp in accordance with the invention.

Referring first of all to Figures 1 to 3, the lamp is shown with a parabolic reflector 1 and with an incandescent lamp 2. the filament of which lies along the axis of the reflector 1 and extends rearwardly from the focus 4 of the reflector. The screen 5 consists of a half barrel or round hood shaped filament 3. As illustrated, the screen 5 is adapted when in the closed position shown in Figure 1 to screen entirely the upper half of the surface of the reflector 1 from light from the filament 3. The lamp holder 7 is mounted at the inner end of a tubular shell 8 attached to the back of the lamp body 9. The screen 5 is attached to a sliding sleeve 10 which may travel backwards and forwards on the tubular shell 8 up to a collar or flange 11 fixed to the front end of the shell 8 when the screen 5 is in the closed position as shown in Figure 1.' The flange 11 also constitutes a back reflector which is made to reflect the light from the space between the lamp holder and the annular opening through which the movable screen slides and is preferably formed with a curvature about the centre 53, this point being the junction of the lines bisecting the angles between the front end of the filament, the inner and outer edges of the reflector 11 and the front edgeof the movable screen 5. This reflector so fo med produces a wide spread beam of moderate penetration and adds materially to the near illumination but in such a way that all the rising light rays are cut off and reflected downwards when the movable screen is in the closed position. Alternatively, if the centre of curvature 11 ofthe back reflector is brought somewhat nearer to the axis of the main reflectorrising light will be produced by the back reflector which will not be cut off by the operation of the movable screen. Any means may be provided to keep the half barrel 5 in the correct angular position; for example, a pin or key carried by the shell 8 may engage a slot in the sleeve 10. The reflector 1 is mounted coaxially with the tubular shell 8 and the lamp holder 7 and is cut to admit the movable screen 5. The arrangement is such that the normal position of the screen 5 is the rearward position shown in Figure 2 wherein the lamp projects a full or complete beam. Normally the screen is pressed into that position by a helicoidal spring 12. Vhen the driver desires to cut down the illumination to a [lat topped beam he is enabled to cause the screen 5 to slide into the closed forward position shown in Figure 1. For this purpose a forked lever 13 with its fulcrum at 14 below the tubular shell 8 is arranged to press upon the rear surface of a flange 15 on the sleeve 10 against which also the spring 12 abuts. The lever 13 has a short arm 1(3- connected to a- Bowden wire 17. Thus when the latter is pulled the forked lever 13 pushes forward the screen 5 as shown in Figure 1.

In Figures 4; to 6, a slight modification of the invention is illustrated, the arrangement being such that the half barrel sha ed 1 screen 5 instead of being capable of being rods 18 and makes thefwhole arrangement rigid. Agtension spring -21'has its fixed end anchored to the bridge bar 20 and its rear movable end to'a pin 22 extendingup- \vardly from" the screen 5. The normal efl'ectis. forthe spring21to contract and draw forward the screw 22 andthe screen into tlieforward position. fHowever, a

."closedupositions shown in full lines in Figure 4: and at the same time stretching the spring '21. Theposition of the filament 3 is substantially the same as shownin Fig- Bowde'n 'wire 17 is provided also attached to the pin 22 and arranged when operated to draw back this pin and the screen 5 to the ures land 2" so -that:when' the screen 5 .is

in the rear; position} the directlight from the-filament is cut-o'fl' fromthe upperpart of. the reflector 1, whereas when thes'creen 5 is allowed to move into the forward .po sition, the reflector projects a substantiallyfull or" "complete beam. Whenthescreen is in the open":lpos'ition the shadow bars produced in the full beam by the guide rods '18 and spiral sprin'g21 can be 'difi'u'sed'and obliterated by the use ofa vertically grooved or-ribbed front-glass. In this figure a lamp bulb of elongated form is shownat 2', such formof bulb being preferable when employing higher candle power lamps for therea son already stated. 1

In the form of lamp-illustrated in Figures 7 and 8, the screen 5 comprises a pairwof folding leaves 5, 5" jpivotally mounted about a hinge 23. The-screen is shown in the: open POSItlOIi n full llIlQS .in Figure '7, 1n the closed position '1n- Figure 8 and in the open position'shown in Figure "9, whereas the closed position is shown in chain lines in Figure 7. It will befinoticed *that' the axis ofthe hinge 23. lies in the vertioal axial" plane of the reflector The front end of the hinge axis is approximately -on the line 24 which joins the front-end of the filament 3 -t-othe mouth "'25 of the reflector 1 vand this front end of the-hinge axis liessomewhat further from theaxisof the reflector 1 than half the diameter of the bulb 2. The hinge axis extends from its front point to 'the reflector l along a ,line lying in i the" said vertical axial plane; which is "approximately normalto the'surface of "-the' -reflector 1 at the point" where the axis meets the reflector.

plane.

near to the car.

or both."

the two leavesare in the closed posit-ion they are folded over the upper half of the hub to form' a flat sided hood shaped cover, as can be seen from Figures? andYS, so that their outer edges rest substantially in the horizontal axial plane ofjthe reflector in lines in that plane'whichcorrespond with thefline ofthe hinge axis in the vertical axial The rearward edges 26 of the leaves 5; 5? are curved outwardly 'slightlyto meet the surface of the reflector 1 when in the closed position and the forwardedges 27 of the leaves maybe curved inwards slightly; these forward edges-fat any'point'lying on the line from the front end of the filament 3' to the'mo'uth 25 of thereflector. When in the '5 open osition the two leavesare folded so that they ;lie "close together near to Vertical axial plane of the reflector {as clearly seen in Figure 9. The leavesfi 5 may also be silvered and polished Wholly or partlyjonthe side next to the filament and it Will be found that the-light reflected from them when iirthe i clos'ed position {produces .increased- -ligliting on the roadway In" this casealso the leaves I may be. perforated to allowsome light to pass. or they maybe reduced in size or shape to; allow a band of: light to pass to. the re flector at either their front orback edges Themechanismemployed for causing the leaves- 5 5 to, fold into the closed position, I is as 1 follows z Af mechanism 'plate 28 say one-sixteenth of an inch thick is formed witha hole of the diameterof the body of thelamp holder 7 and passes over the lamp holder 7 uponwhich it is clamped by a nut against the back surface of the'rear portion of reflector 25. 1 The 'inecl' an'ism plate 28l1as fo'rmed in it a pair, of arcshaped slots=30 above an opening or hole in the wall of the reflector 1. The leavesb 5 each carry an actuating member 31 which has a flat portion by means of which it is riveted to; the respective leaf. and a rear- Wardly projecting pin 32 which extends'out through one of the slots 30. The slots 30 are circular so that when the blades turn aboutthe hinge 23 the pins 32pass'along the slots 30.

The; mechanism plate 28 has lateral turned over portions 33 vwhich serve to form a guide fora further. plate 34' arranged to slide up and :dow'n on theback surface of the plate 28. Thepla te 28 at its upper edge has [a turned ever part 35 and the plate 3 1 has -a corresponding turned over part 36.

A L- pwardly extending stem 37 s d to thepart 36 of .the 1 t. and passes through ahole in the part 35 of the fixed mechanismplate 28 and. thus serves as an additional; guide for the sliding 'pl'ate 3 1.

RA helical spring :38 surrounds the 37 abutting at its lower end on thefixed'part of the mechanism plate and atits upper end against a washer 39 fixed on the upper end of the stem 37. Thus normallythe spring 38 presses the stem 37 to its upper limit and maintains the sliding plate'3 l in its uppermost position. The latter, however, can be drawn downwardly from the drivers seat by means of a Bowden wire 17 secured to the washer 39 carried by the stem 37, thus compressing the spring 38. Immediately the'Bowden wire mechanism'is released the spring 38 thrusts the plate 34- again into its uppermost position.

The function of the plate 34; is to cause the pivotal movement of the blades 5, 5 and to that end the plate 3& has a pair of slots through which the pins 32 also project. The slots are in the main horizontal although their inner ends are in clined downwards somewhat. Thus when the spring 38 pushes the plate 34; to its uppermost position the slots 10 cause the pins 32 to be pushed inwards and the in clined inner parts of the slots ensure that the blades 5, o are held firmly in contactin the position shown in Figure 9. On the other hand, when the Bowden w re mechanism draws down the plates 3 1 the pins 32 tend to fall downwardly in the slots and, of course, the slots 10 allow of that movement so that when the blades reach the full closed position the pins 32' have reached the bottom of the slots 30.

In the form of lamp shown inFigures l0 and 11 the screen 5'is a hood shaped cover in the form of a segment of a spherical surface. The front edge llis straight as seen in Figure 11 and surrounds the bulb fairly closely while the rear edge 12 has a concave curvature. The reflector 1 has a curved slot 43 shaped to correspond to the curvature of the screen 5 and as the latter .is mounted about a pivot it it is capable of passing out through the slot 4-3 into the open position indicated in chain lines in Figure 10 at 5 In the closed position shown in full lines in Figure 10 the screen 5 is substantially within the reflector 1, its

front edge ll lyin approximately on the line 24: oining the' 'ront end of the filament 3 to the mouth 25 of the reflector 1. The screen 5 has at one side, as clearly seen in Figure 11, a cylindrical boss rigidly fixed to it as by riveting or brazing and integral with this boss is a double armed lever 46. The boss 15 is journalled on the axis M about which the screen turns and the rear arm of the double armed lever l6 is anchored to a tension spring 47 fixed atits other end to a downwardly projecting fixed bracket 18. Thus the normal tendency of the spring 47 is to draw the screen 5 into the open position, that is the position shown in chain lines in Figure 10. However, a Bowden wire 17 is fixed to the forward arm of the lever 46 and when operated from the driv-ers seat draws this forward arm downwards and rocks the screen 5 into the closed position shown in full lines in Figure 10.

Referring now to-Figure 12, a form of lamp is shown which is similar to that shown in Figures 1 to 3 and 4 to 6 in that the screen is a half barrel shaped or semicylindrical screen which is in fact arranged to be moved rearwardly to the outside of the reflector 1 and the construction is simi lar tothat shown in Figures 10 and 11 in that the screen 5 is rocked about a horizontal transverse axis 44, although in this case the axis 4 1 does not intersect the 'central axis of the reflector 1, but is situated towards the top of'the lamp and approximately above the central plane of the screen 5 when the latter is in the closed position. The screen 5 is shown in the closed position in full lines and is shown in the open position in chain lines at 5. It is carried upon an arm 50, which latter has an inturned portion 51 secured to the rear of the screen 5. In this case also the screen is operated by a Bowden Wire 17 and is returned to the open position outside the reflector 1 by a tension spring 52. It is not necessary to state further particulars of the form shown in Figure 12 as these can be readily appreciated from the study of the construction shown-in Figures 1 to 3 and 10 and 11.

If the movable screen 5 is shortened a narrow angle rising light half beam will be producedabove the centre of the flat topped beam of a width and intensity depending on the amount of shortening of the movable screen. If the movable screen is shortened on one side only of the vertical axial plane anarrow angle quarter beam will be produced and if the movable screen is cut away entirely on one side a full three quarter beam will be obtained. Again, by suitably perforating the movable screen a subdued rising light half beam will be produced and if these perforations are confined to one side of the central axial plane only, a subdued rising light quarter beam will be obtained, or by suitably perforating both sides rising light may be obtained of different intensity on each side.

Any form of concentrated light source may be used with the arrangement though a single pillar incandescent filament focussed as described is the preferred form. For instance, a double pillar filament or V-shaped filament may be used or even a pillar filament mounted to lie across the axis of the reflector 'canbe focussed to produce a fair result.

An electric lamp bulb havin an attachment secured to the lamp cap w ioh engages a lamp holder mounted in a standard position relatively to the surface of the reflector is particularly useful in combination with the devices herein described and such a combination constitutes a part of the present invention. An electric lamp bulb having a fitting piece for focussing bulbs of the form set forth in the specification of my British Patent No. 204,7 74 and employed witha special lamp holder in accordance with the speci fication of my British Patent No. 204,464 are particularly suitable for use with this invention. The lamp holder 7 shown in all of the examples illustrated is a lam holder of this type and it will also be note that in each case the lamp'bulb employed is shown with a fitting piece 49 of the kind just referred to. Having thus described my invention, what I claim as new and desire to secure by Letters Patent is V A headlamp for motor vehicles comprising a lamp body, a parabolic reflector mounted therein, a source of illumination extending from the focus of said reflector along its axis, a movable screen mainly formed as a zone from the central portion of a hemisphere and polished and plated on its inner surface, and so disposed that, when the screen is in theoperative position, the centre of the sphere lies approximately on the axis of the reflector and between the centre of the light source and that end of it which is farthest from'the focus of said reflector and an actuating mechanism operatively connected to said screen to cause the latter to move between its two extreme p0sitionsone in which it intercepts the rays from said source of illumination to or from substantially one half of said reflector and the other in which it allows the light free access to substantially 1 HAROLD WORKMAN. 

